It is known that 4,6-dialkoxy-2-cyanomethylpyrimidine is an intermediate for herbicide synthesis (reference is made to Patent Literatures 1 and 2). For production of this 4,6-dialkoxy-2-cyanomethylpyrimidine, there is known a method of reacting a cyanoacetic acid ester with a 4,6-disubstituted-2-methylsulfonylpyrmidine in the presence of a base to obtain a 2-cyano-2-(4,6-disubstituted pyrimidin-2-yl)acetic acid ester and then subjecting the ester to hydrolysis at 150° C. and subsequent decarboxylation in an aprotic solvent in the presence of 2 equivalents of water and a catalytic amount of an inorganic salt such as sodium chloride or the like (reference is made to Patent Literature 1). This method, however, has had problems in that a high temperature of 150° C. is required and the yield is low at 50 to 60%.
There is also known a method of reacting 2-chloromethyl-4,6-dimethoxypyrimidine with sodium cyanate (reference is made to Patent Literature 2). However, this method is also low (58%) in yield and is not suitable for industrial application.
Thus, there has been known, for production of 4,6-dialkoxy-2-cyanomethylpyrimidine, no method utilizing the high reactivity of tert-butyl 2-cyano-2-(4,6-dialkoxypyrimidin-2-yl)acetate in the presence of an acid. This tert-butyl 2-cyano-2-(4,6-dialkoxypyrimidin-2-yl)acetate is a novel compound not described specifically in the Patent Literatures 1 and 2.